A method and a device for operating an internal combustion engine provide that a value for a first performance quantity of the internal combustion engine is modeled as a function of at least one second performance quantity different from the first performance quantity, e.g., a charge of the internal combustion engine. This modeling is corrected as a function of a comparison of the modeled value for the first performance quantity with a measured value for the first performance quantity. The correction is performed differently for different operating points of the internal combustion engine.